If we don’t believe there is such a thing as an objective ethical standard, if the territory doesn’t exist, then I fail to see the point in even discussing ethics.
There is no such a thing as an objective ethical standard. However, each agent has her own ethical standard which is meaningful to discuss. For humans, this moral standard often includes a “preference utilitarian” component i.e. we want the preferences of other morally significant agents to be satisfied (where the definition of “morally significant” is probably quite complicated but seems to involve intelligence and possibly similarity to humans) - but not at all costs (i.e. there are other components in our utility functions as well).
There is no such a thing as an objective ethical standard. However, each agent has her own ethical standard which is meaningful to discuss. For humans, this moral standard often includes a “preference utilitarian” component i.e. we want the preferences of other morally significant agents to be satisfied (where the definition of “morally significant” is probably quite complicated but seems to involve intelligence and possibly similarity to humans) - but not at all costs (i.e. there are other components in our utility functions as well).